I have been working on my k5 beast and gave her an up grade on her rear end with a newer rear fender..I have a 1986 kx 500 and the rear fender I bought that fits nice with little mods is from a kx 450f 2006-2008 model...all I had to do to make it fit was trim the edges off so she fits under the sub frame...but where the brackets are for the sub frame bolted right on just has to cut a little bit to make it fit, it came out great looks real nice too....am sure other years fit too but i tried the 94 kx 250 rear fender on it and it was just way too big, the 86 models have a narrow sub frame where the bolts mount for the rear brackets...just joined will post pics of it later...thanks, Craig